Boiler.



T. J. SHEA.

BOILER.

APPLICATKON FILED FEB. 13. 1914.

Patented Oct. 26, 1915.

pm E S s E N H W COLUMBIA PLANOGRAPH c0, WASHINGTON. 15:11.

an ormp.

' 'JIHQMZAS J. fiHZEA, F PORTLAND, OREGON.

BOILER.

Specification of LettersBatent.

Patented em. as, rare.

Ap'plicationfiled February 13, I914. SerialNo. 818,460. a

and State of Oregon, have invented a certain new and useful Boiler; andI do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others'skilled in theart to which it appertains to make and use the same, reference being hadto the accompanying drawings, and to the characters of reference markedthereon, which form apart ofthis specification.

This invention relates to boilers, and particularly to boilers of thevertical type, commonly known in some localities as fdonkey boilers, andcombining both water tubes and fire tubes in their construction.

The object of my invention is the provi sion of an improved'boiler ofthe character described, which is particularly designed for use inlogging camps, but is not restricted to such use, and is capable ofhaving oil, Wood or coal used as fuel therein, and also of being easilytransported from one place to another.

The invention is fully described in the following specification, andwhile, in its broader aspect, it is capable of embodiment in numerousforms, a preferred embodiment thereof is illustrated in the accompanyingdrawings, in which,-

Figure 1 is a central vertical section of a boiler embodying theinvention taken through the fire door. Figs. 2 and 3 are cross-sectionsthereof on the lines 00, a? and y, y in Fig. l, with the water tubes inthe latter removed, and Fig. 4 is a partial crosssection on the line ain Fig. 1.

Referring to the drawings, 1 and 2 designate the inner and outer shellsof a boiler, which may be of any suitable size or shape in cross-sectionand have their sidewalls held in rigidly spaced relation by stays 3, orin any other suitable'manner, to provide the water-leg space 4therebetween. The inner shell 1 forms the fire-box of the boiler and isprovided adjacent to the lower end of the outer shell with an inturnedledge 5 which terminates at its inner edge in a downwardly projectingflange 6 forming an opening 7 in the bottom of the firebox, which is ofless diameter than the diameter of the fire-box and may have thecustomary grate 8 disposed therein if wood, coal or other ash-producingfuel is used. The openmg 7 is intended to communicate at its lower endwith an ash-pit (not shown), such ashpit being customarily provided inthe base upon which the boiler is mounted. The lower edges of the outershell 2 and flange 6 are connected by a flange '9 of annular or othersuitable form conforming to the bottom shape of the boiler. The ledge 5,flange 6 and bottom plate 9 cooperate to form an enlarged water space atthe base of the water-leg 4, such space extending inward underthemarginal edge portion of the firebox, as shown.

The crown pl'ates 10 and 11 of the inner and outer shells 1 and 2 arevertically spaced, and one or more rows of vertically disposedfire-tubes 12 connect such plates, preferably adjacent to their outeredges, and open communication between the interior of the fire-box andthe atmosphere.

Disposed within the fire-box are one or more rows of upright water tubes13, which rise fromthe ledge 5, through which they have communicationwith the base portion of the water-leg 4, and extend at their upper endsthrough the crown-plate 10 into communication with the upper portiono'fthe water chamber, or the space between the plates 10 and '11. "Thesetubes are slightly inwardly inclined from their lower ends upwardly toenable them to communicate with the upper water space of the boilerwithin the row or rows of fire-tubes 12. The rows of water-tubes 13preferably extend entirely around the innermarginal portion of thefire-box, except for the space in register with the fire-door 14, andcooperate to form an interior fire-chamber. The tubes are preferably.arranged in staggered relation to baffle the flames and highly heatedproducts of combustion as they pass between and around the same to findan exit from the fire-box through the fire-tubes 12, which, as will benoted, are disposed without the upper ends of the water-tubes. Thewater-leg 4 is pro vided immediately above the fire-door 14 with aninwardly projecting water-pocket 15, which is formed by a casting ormember 16 secured to the edges of an opening 17 in the shell 1, andopening communication between the top of this pocket and the upper waterspace of the boiler are a plurality of short water tubes 18. It is thusevident that the Water-tubes 13 and 18 cooperate to entirely surroundthe upper central por- 5' said overhead water space, water tubes extionof the-fire chamber and that the space adjacent to and below thefire-door 14 is not obstructed by water-tubes. V I

A steam-dome 19 is mounted centrally on the outer crown-plate 11 withinthe set of fire-tubes 12, and has communication with the upper waterspace of the boilerthrough an opening 20 in the crown plate. If thesteam-dome 19 is omitted the fire-tubes 12 will project through thesteam space of the boiler 'and serve to superheatvthe steam.

It is found in practice that this form of boiler is'inexpensive, andcomparatively out departingfrom the spirit thereof.

Having thus described my invention, what I claim'as new, and desire tosecure by Letters Patent,iis,. a

1. In a boiler, inner and outershells forming an interior fire chamber,an overhead water space, a water leg and an enlargement atthe lower endof the water leg, a closed steam dome mounted on the top of the outershell in communication at its bottom with tending fupward through thefire chamber 7 and opening communication between said Copies of thispatent may be obtained for water leg enlargement and the overhead waterspace, said water tubes being arranged in a circular set and inwardlyinclined from their lower ends upwardly, fire tubes extending upwardthrough the overhead water space and opening communication between thefire chamber without the upper ends of the water tubes, and theatmosphere around said steam dome, substantially as described.

2. In a boiler, inner and outer shells form ing side upper and lowerwater spaces, a fire chamber, a door opening in the side of said chamberand an inwardly extending water pocket above the door in communicationwith the side water space, a steam dome onthe top of the outer shellbeing of smaller diameter than the outer shell, a set of fire tubesextending from the outer upper portion of the fire chamber through theupper water space to the atmosphere around said dome, a set of longwater tubes extending upward on an inward incline from the lower portionof the side water space to the upper water space, and a set of shortwater tubes extending upward on an inward incline from said water pocketto the upper water space,

said long and short tubes having their upper ends communicating with theupper Water space at points located within the set of water tubes,substantially as described.

In testimony whereof, I have hereunto signed my name to thisspecification in the presence of two subscribing witnesses.

V THOMAS J SHEA.

Witnesses:

MAURICE W. Snrrz, V. L. CLARK.

five cents each, by addressing the Commissioner of Patents, Washington,I). C.

